Could not resolve hostname xxx: Bad address

Peter Hancox
Sun Apr 20 09:43:00 GMT 2014

After running strace I was able to determine there was a problem calling

This led me to a recent thread "1.7.29-2: Exception from
cygwin_gethostname".  Replacing cygwin1.dll with the snapshot build
referenced in that thread fixed my problem also.

-----Original Message-----
From: Peter Hancox
Sent: Sunday, 20 April 2014 16:52
Subject: ssh: Could not resolve hostname xxx: Bad address

OpenSSH under Cygwin just started failing with "Could not resolve host
address".  Originally this was actually using scp to transfer a file to a
local host, however, the attached example is a simplified test case.
Output from cygcheck attached.

PS D:\WorkArea\Cygwin> ssh -vvvv OpenSSH_6.6, OpenSSL 1.0.1g 7
Apr 2014
ssh: Could not resolve hostname Bad address PS
D:\WorkArea\Cygwin> ping

Pinging [] with 32 bytes of data:
Reply from bytes=32 time=19ms TTL=59 Reply from bytes=32 time=19ms TTL=59 Reply from bytes=32
time=19ms TTL=59 Reply from bytes=32 time=20ms TTL=59

Ping statistics for
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round
trip times in milli-seconds:
    Minimum = 19ms, Maximum = 20ms, Average = 19ms

Although this particular test was run from within Powershell, same results
from command shell and bash.

I am aware of the recent issue with mixed case host names but shouldn't be
relevant in this case and OpenSSH and all installed Cygwin software is at
latest versions.  Have reinstalled OpenSSH just to be sure and still fails.

Note that I have exactly the same Cygwin (x64) installed on a Windows Server
2012 instance running on Amazon EC2 and it continues to work fine.

Not sure when this broke but I probably haven't attempted to use ssh from
this machine for a couple of months.  One thing that has definitely changed
since the last use (and is different to the working instance) is
installation of Windows 8.1 Update 1 patch.

Running with "-vvvv" doesn't give any additional information other than
version numbers.  Nothing in Windows event logs.  Suggestion for debugging



DELTA Technology Consulting       Telephone: +61(2)9420-1800
PO Box 1383 Lane Cove             Facsimile: +61(2)9420-1899
NSW 1595 Australia                WWW:

Problem reports:
Unsubscribe info:

More information about the Cygwin mailing list